OF mental health care and mentally ill

The Distinction BetweenNormaland Disordered Personality

Empirical research on the DAPP has yielded several findings that are directly relevant to the distinction between normal and disordered personality: (a) the structure of primary and secondary personality traits is similar in clinical samples of patients with personality disorder and general population samples; (b) the distribution of scores in general population and clinical samples overlap substantially with no evidence of discontinuity; (c) the secondary structure of personality disorder identified using the DAPP-BQ is remarkably similar to models of normal personality traits; and (d) there appears to be genetic continuity between traits representing normal and disordered personality. From a trait perspective, the distinction between normal and disordered personality appears to be quantitative rather than qualitative. These findings are consistent with the substantial literature indicating that personality disorder traits represent the extremes of normal variation and with a dimensional rather than a categorical representation of individual differences in personality disorder (Livesley, 2003; Livesley, Schroeder, Jackson, & Jang, 1994; Widiger, 1993).

Although a dimensional representation of personality disorder is consistent with empirical findings, adoption of a dimensional classification would create the conceptual and practical problem of how to determine when an extreme position on a trait dimension is indicative of personality disorder. There are four possibilities. Personality disorder could be viewed as: (a) extreme personality variation; (b) maladaptive expressions of extreme personality variation; (c) specifi c constellations of extreme traits; or (d) personality dysfunction defined independently of trait extremity. The fi rst three approaches conceptualize personality disorder largely in terms of extreme variation. In contrast, the latter approach seeks to define disorder using criteria that are independent of trait function.